When the U.S. Census Bureau releases five years of community data Tuesday, government planners, nonprofit organizations, educators, researchers and curious residents will be able to find, for the first time, detailed information about even the smallest Long Island communities.

The American Community Survey offers insight into changes in household size, housing values, immigrant populations, racial makeup, age, income, poverty and other demographic issues from 2005 to 2009.

Past surveys have limited data to one or three years and to areas with populations of 20,000 or greater. The new data will cover communities with even smaller populations, providing a snapshot of life in villages, hamlets and communities like Shelter Island, Patchogue and Mineola.

Among those eager to study the information is Seth Forman, chief planner for the Long Island Regional Planning Council, who spoke with Newsday about the significance of the data. Excerpts from his conversations address what questions the data might answer and what it may reveal about where we live and who we are:

Significance of a 5-year survey

Forman: "The one-year data only exists for places that are 65,000 [in population] and over. That excludes every village and hamlet on Long Island and includes only the two counties, the three Nassau towns and the five west end Suffolk towns.

"The three-year estimates, with a 20,000 population threshold, give us data on only 15 or 16 communities in Nassau, out of 142. That means 89 percent of Nassau communities are not covered. In Suffolk, it's only 17 out of 169, which is only 10 percent of the total. The townships do get covered, except Shelter Island, in the three-year. [What's left] are a large number of small neighborhoods or rural populations that we know virtually nothing about.

"The five-year data will tell us about the smallest communities and neighborhoods."

Hispanic population

Forman: "While we know that, for example, Long Island, like the rest of the nation, has become very much more Hispanic, we don't really know all of the communities that have been impacted by Hispanic migration. We know anecdotally and by experience that the East End seems to have a very high Hispanic population at this point. We know that the Village of Greenport was so frustrated with not having good census information about this that they took it upon themselves to conduct their own survey [in 2006-07].

"Expect the Hispanic count to be more accurate for every place."

Asian population

Forman: "We know that school districts covering six communities in Nassau County, most in the North Shore, have pupil populations that are 20 percent or more Asian. That includes Jericho, Great Neck, Searingtown, Roslyn, Hicksville and New Hyde Park. But we really don't have detail of country of origin or year of entry of the foreign-born to these places.

" 'Asian' is a very broad category, covering Indian and Pakistani to Thai, Korean and Chinese. The five-year data will show country of origin or ancestry. It will be interesting to look at Middle Island, where there's a large Indian/Pakistani population, but we don't know the actual numbers."

Growth and development

Forman: "Eastport and Manorville in the '90s were the fastest-growing places in Suffolk, in terms of residential development. We know, from building permits, they've declined, in terms of construction. But we don't really know the details of residential household occupancy, like the size of the average household.

"I think we'll see there is still a preference for suburban living, of having the single-family home. Automobile use will probably remain a preference and may even grow."

Age and relocation

Forman: "There have been retirement communities built in these areas in the last 20 years, so we don't know how that's changed the demographic balance. There have been changes in medical technology and life expectancy, so that the first occupants of the 1960s and 1970s in places like Commack and East Northport are over 65. So in those places, we really don't know in the last 10 years if they've sold their houses and left."

Housing

Forman: "Tenure will be the big thing - how long someone has been in their house. The survey will show us renting versus owning. If the percentage of home ownership goes below 80 percent, that will be significant.